Dockhand plugged my 30A 120 into 30A 250

[stormalong]

Originally Posted by rgleason

Stormalong, what a wizard, 10 seconds? Thanks.

I suppose these are the connectors used on UK docks, but they say 110v? I thought it was 230v or 240v... below they state "240 volt or 110 vol"
Is that the type of male/female needed to make a short adapter cable with a US shorepower connector?


Later:
The cord looks like it is intended for the the 15amp 120vac side. There is a cord for the shorepower side, but it would not meet marina standards and the plug is not a marine plug. So there are plug issues to work out on both input and output.


Only 58L though.

This would take the 240 volts from the dock and output 110 volts. It could be used for a non US boat to go the other way if needed. Isolation transformers will work either way, unlike autotransformers. You are still dealing with 50 Hz but I never had a problem running 60Hz devices at 50 Hz.

The common way to use these is to leave it on the dock next to the power post. Have a short cable to the xfmr from the power post and a short adapter cable to connect to your shore power cable. So you need to make up two short adapter cables and you are in business. Oh and chain it to something sturdy - these things have legs.

PS. Maybe it took 15 seconds.

[masonc]

Originally Posted by rgleason

My search for "240vac to 120vac isolation transformer 3kw" turn up a bunch of Isolation Transformers, several are 3kva which is not the same

It's the same. Transformers are traditionally rated in KVA to accommodate power factor calculations but in single phase applications you don't need to be concerned with power factor.

[masonc]

Originally Posted by stormalong

I found this through google UK in about 10 seconds.


https://www.amazon.co.uk/Faithfull-T...29SM7GTCGKG8X7

That's exactly what ward on my boat when I got it. The previous owner sailed in Europe and Asia. Unfortunately the installer wired both 120v plugs to the shore power breaker, unplugging either plug would leave live pins. Be aware it is only rated at 1.65KVA, if 1.5kw is adequate for your boat, this will work. Just wire one plug.

[Lake-Effect]

Originally Posted by masonc

It's the same. Transformers are traditionally rated in KVA to accommodate power factor calculations but in single phase applications you don't need to be concerned with power factor.

You can have power factor issues even with single phase, but the average boat isn't going to have many of the sorts of loads that would be a problem.

[mitiempo]

Originally Posted by rgleason

My search for "240vac to 120vac isolation transformer 3kw" turn up a bunch of Isolation Transformers, several are 3kva which is not at all the same.
3kVA Isolation Transformers | Newark element14
They range in price from $300 -$1200
Would this one work?
SP3000MQMJ - Isolation Transformer, 3 kVA, 120V, 240V, 25 A, 1 x 240V, 1 x 480V, HPS Spartan Series

I suppose it is not ABYC certified so we should not have it on the boat.

Victron has an isolation transformer that will produce either 115 or 230 volts regardless of input voltage. The 3600 watt model on this data brochure.
https://www.victronenergy.com/upload...formers-EN.pdf

Sells for about 1000 Cdn, so about 700 US.

As a bonus bad wiring on other boats or the marina itself will not cause any corrosion problems on your boat.

[john61ct]

Another approach is to furnish the boat with minimal "stick & brick home" appliances designed for shore power, go native DC as much as possible.

Go for efficiency, as if the boat will mostly be used off-grid for weeks / months at a time.

Primary design goal is DC energy efficiency to live mostly off batteries, minimum usage of any fossil fuel charge sources, ideally just an hour a day or a few hours a week, only needed in cloudy weather.

Thus minimum need for inverters, maybe one or two small ones that are located at and dedicated to the mains device they power, turned on and off with that device as needed. In fact it becomes easy to mix & match mains appliances running at 110 or 240 as purchased anywhere you happen to be when one fails.

This approach can mean little to no actual AC wiring on the boat, the only connection made when docked is via the battery charger.

Which could then be, as with Sterling, a global/universal AC input unit, 100-240V / 47-64Hz, can be plugged in anywhere in the world with just a simple plug adapter.

This approach is less likely to be used for those who want invection stoves, microwaves and dishwashers aboard, call going without such mod cons "camping", as if disparaging the idea.

But it could be.

[skenn_ie]

Originally Posted by stormalong

No, a voltage sensitive relay is for charging batteries.

A big issue for wiring your boat for multiple voltage input is that you never want to apply 220 volts to your 110 volt boat wiring. Even if you are careful sooner or later you will turn something on that should not have 220 volts on it and it will be destroyed.

A better solution is a separate transformer for the 220 power source. In the UK they have regulations restricting outdoor power tool voltage and they sell some very nice isolation transformers in yellow cases.. The transformers come in 3 kw and up.

Very few, if any, of those yellow transformers are isolation transformers. They are "auto-transformers", where the 110 is just a tap half way "up" the winding. Running off shore power for any length of time without an isolation transformer (preferred) or Earth isolation device (not so good), WILL cause galvanic damage to prop, shaft etc.
Voltage sensitive relay can disconnect everything if you plug into the wrong voltage. As with ANY protection device, it may not be 100% effective though. Relays take a finite amount of time to switch. However, it will protect devices that you switch on AFTER the shore connection is made.

[hpeer]

Originally Posted by john61ct

Another approach is to furnish the boat with minimal "stick & brick home" appliances designed for shore power, go native DC as much as possible.

Go for efficiency, as if the boat will mostly be used off-grid for weeks / months at a time.

Primary design goal is DC energy efficiency to live mostly off batteries, minimum usage of any fossil fuel charge sources, ideally just an hour a day or a few hours a week, only needed in cloudy weather.

Thus minimum need for inverters, maybe one or two small ones that are located at and dedicated to the mains device they power, turned on and off with that device as needed. In fact it becomes easy to mix & match mains appliances running at 110 or 240 as purchased anywhere you happen to be when one fails.

This approach can mean little to no actual AC wiring on the boat, the only connection made when docked is via the battery charger.

Which could then be, as with Sterling, a global/universal AC input unit, 100-240V / 47-64Hz, can be plugged in anywhere in the world with just a simple plug adapter.

This approach is less likely to be used for those who want invection stoves, microwaves and dishwashers aboard, call going without such mod cons "camping", as if disparaging the idea.

But it could be.

This is the route I’ve taken. I do have a 2,000 watt inverted but seldom use it. We have a steel boat, when in the dock we plug into a battery charger, this provides the isolation to minimize electrolysis.

The biggest 120VAC draw we have is my wife’s laptop, it’s old and has a huge screen. Energy hog. Beyond that theninverter is for some short term tool use. Any significant use and I lug out the Honda. The boat has no native AC loads, nada.

We don’t find ourselves deprived (as opposed to depraved, which is much more fun) in any manner. No sense of longing for any new toys. Simplicity.

[rgleason]

skenne ie

Very few ...yellow transformers are isolation transformers. They are "auto-transformers", where the 110 is just a tap half way "up" the winding. Running off shore power for any length of time without an isolation transformer (preferred) or Earth isolation device (not so good), WILL cause galvanic damage to prop, shaft etc.

Thanks, not the route to go I think.


john61ct
Thank you. Victron Isolation Transformer seems to be one of the best choices for this, it is automatic and protects the boat and equipment and provide galvanic isolation and is an approved configuration.


hpeer and john61ct

..No appliances designed for shore power, DC only, off-grid, design goal is DC energy efficiency..use batteries, solar, fossil fuel charge an hour a day or a few hours a week, small inverter only, little to no actual AC wiring on the boat, the only connection made when docked is via the battery charger. Which could then be, as with Sterling, a global/universal AC input unit, 100-240V / 47-64Hz, can be plugged in anywhere in the world with just a simple plug adapter.

This is the approach I would like to take. However there are some wiring problems. See this attempt please:
1. For connection of the Charger only to a "global AC power source", how would you suggest I do that, when I have wired the unit up to a new ELCI 120vac Panel 15 amp circuit breaker with Galvanic Isolation? I would like to make this easier if possible.

• I don't want to plug into 240v shorepower as I am set up for 120v and not 240v 50hz or whatever.
• Wire the charger supply line with nema male/female connectors?
  
  • Marinco Locking 15A Male Plug Model # 206128 Charger side
    
  • Marinco Locking 30A Female Receptacle Model # 319954 in a box from the 120vdc Power Panel.
    
• Disconnect the unit from the 120 AC Panel, plug it directly into my existing shore cable. Then plug a short adapter cable with a Marinco Locking 30A 125v Female Model # 1873926 into the other shorepower end of the cable . Then purchase an adapter suitable for the dock shore connection and wire it up. Plug it in. Would this work?
  
• What am I missing?
  • Bypassing ELCI 120vac Panel and 15amp Circuit Breaker and GFI protection. West Marine Article
    
  • Bypassing Galvanic Isolator or Isolating Transformer. West Marine DIY Shorepower
  • Proper shore power connector plug for the International Dock fitting.
  • Proper wiring instructions.
• This Use might be a good reason to increase the Sterling Pro Ultra Charger to 12vdc 60a, but I think I will stick with the 40a.
  

[skenn_ie]

Originally Posted by hpeer

This is the route I’ve taken. I do have a 2,000 watt inverted but seldom use it. We have a steel boat, when in the dock we plug into a battery charger, this provides the isolation to minimize electrolysis.

The biggest 120VAC draw we have is my wife’s laptop, it’s old and has a huge screen. Energy hog. Beyond that theninverter is for some short term tool use. Any significant use and I lug out the Honda. The boat has no native AC loads, nada.

We don’t find ourselves deprived (as opposed to depraved, which is much more fun) in any manner. No sense of longing for any new toys. Simplicity.

MOST battery chargers, but not all, provide isolation. Buzz between negative output and AC ground before A.S.S.U.ME.ing.

Laptops and phones can effectively run off DC-DC converters, buck or boost, depending on battery and device voltages.

[rgleason]

International plugs and power
https://shop.pkys.com/International_c_301.html

Pin and Sleeve
https://www.stayonline.com/reference...rnational.aspx

Where to get these connectors?
The same website maybe?
https://www.stayonline.com/custom-outdoor-cords.aspx

Also PKYS.com 32a250vac for European
https://shop.pkys.com/Victron-Boat-P...ms_p_3963.html

I don't see that the Sterling ProCharge Ultra are isolated.
http://www.sterling-power-usa.com/st...y-charger.aspx

Sorry what does this mean exactly?
"Buzz between negative output and AC ground before A.S.S.U.ME.ing." I know it is a warning. Do I cross connect something to check?

What about a fuse or circuit breaker?

[john61ct]

Originally Posted by hpeer

The biggest 120VAC draw we have is my wife’s laptop, it’s old and has a huge screen. Energy hog.

Less so if you just give it its native DC current

[stormalong]

Originally Posted by mitiempo

Victron has an isolation transformer that will produce either 115 or 230 volts regardless of input voltage. The 3600 watt model on this data brochure.
https://www.victronenergy.com/upload...formers-EN.pdf

Sells for about 1000 Cdn, so about 700 US.

As a bonus bad wiring on other boats or the marina itself will not cause any corrosion problems on your boat.

NO NO NO Read the specs. These transformers do not automatically convert from 220 to 110, They stabilize the voltage.

This will do nothing to convert voltages.

[stormalong]

Originally Posted by skenn_ie

Very few, if any, of those yellow transformers are isolation transformers. They are "auto-transformers", where the 110 is just a tap half way "up" the winding. Running off shore power for any length of time without an isolation transformer (preferred) or Earth isolation device (not so good), WILL cause galvanic damage to prop, shaft etc.
Voltage sensitive relay can disconnect everything if you plug into the wrong voltage. As with ANY protection device, it may not be 100% effective though. Relays take a finite amount of time to switch. However, it will protect devices that you switch on AFTER the shore connection is made.

It may be the case that these are autotransformers but that and electrolysis have nothing to do with each other. Electrolysis is a different topic than what we have been discussing here. The use of an autotransformer does not automatically cause electrolysis.

Electrolysis is caused by miswiring the boat so that the neutral and the ground are at different potentials. Reversing hot and neutral is the usual cause and it is usually on your boat or a neighboring boat.

[wsmurdoch]

Originally Posted by skenn_ie

Very few, if any, of those yellow transformers are isolation transformers. They are "auto-transformers", where the 110 is just a tap half way "up" the winding.

All the yellow plastic box tool transformers I saw during the five years I worked in the UK had separate primary and secondary windings. The primary was 240V and the secondary was 110V center tapped to earth (55V-0V-55V). But, I was working on serious construction projects with a health and safety staff.

The transformers (and the 110V tools) were routinely checked in the site electrical shop. I saw the yellow boxes when they were opened. Under the cover was the wiring and the back of the sockets and the circuit breaker. The transformers themselves were embedded in the bottom of the box and were not visible. I do not know if there was a grounded isolation screen between the two windings.

I looked at this internet site. Their tool transformers (they have other types of transformers) are made to a BS specification and claim to have separate windings. The 3.3kVA tool transformer is not a small thing even though it has an intermittent rather than continuous rating. It weighs 22kg.
110v transformers,110 volt transformers,Transformers,110v transformers,site transformers.knighton tools